On a bicycle, the cassette comprises a series of sprockets which attach to a hub driver of the rear wheel. The cassette comprises a series of appropriately sized sprockets which are typically chosen for a specific riding style and/or a riding location. For example, a cassette with a series of smaller sprockets is useful for fast riding and in a flatter location, while a cassette with a series of larger sprockets can be useful for climbing and in a hilly location. The cassette with the desired number and size of sprockets is typically attached to the hub driver body using a locking ring for securing the whole cassette to the hub.